Old cable data sheets.

[Gnasher]

Hello

I understand that this may be an impossible one to answer, but I have been surprised on many occasions with what info is out there if you only ask. So here goes.

I am trying to locate historical cable data sheets for paper lead cables that were probably installed in the 1960s

I think that the manufacture was probably BICC who are no longer in existence. I have done a google search and found a company in Cairo who carry the BICC logo. I have emailed them but as yet had no reply.

The cables are imperial 2 core 19/0.64 and 19/1.53 lead sheathed,

The specific info I am looking for is the ohmic values of the conductors and lead sheath. Similar to the Table 11 in the onsite guide R1 + R2 values.

Thanks

Steve

 

[Lucien Nunes]

Yes, one of the MMs that won't be working any time soon due to disintegrated Mazak castings in the tuning gang.

 

[freddo]

A friend had one, the mazak was also in a terrible state and crumbling, the moving parts seized.

 

[Gnasher]

Let's try to validate the lead CSA for the older BIC 19/.064 by calculating it both from the stated dimensions and from the linear weights.

Lead O/D = 0.85 ins. = 21.59mm
Lead I/D = 0.85 - (2 * 0.08) = 0.69 ins. = 17.53mm
Lead CSA from dims = ((21.59 / 2)² - (17.53 / 2)²) * Π = 125mm²

Weight of twin cable = 43.75cwt / 1000 yds. = 2.431kg/m
Weight of 19/.064 copper = 720.3 lbs / 1000 yds. = 0.3573kg/m
Weight of lead (ignoring paper) = 2.431 - (2 * 0.3573) = 1.7164kg/m
Lead density (ignoring alloying elements) = 11.34g/cm³
Lead volume per metre = 1716.4 / 11.34 = 151.4cm³
Lead CSA from weight = 151mm²

Lead resistivity 2.2E-7 Ωm @ 20°C ignoring alloying.
Resistance of 125mm² lead = 2.2E-7 / 125E-6 = 1.76mΩ/m
Resistance of 151mm² lead = 2.2E-7 / 151E-6 = 1.46mΩ/m
Resistance of 19/.064 TC = 0.4195Ω / 1000 yds. = 0.459mΩ/m

I'll do the later Enfield cable in the morning unless someone wants to save me the effort.

Lucian

This brilliant. I cant believe you have gone to this amount of effort to help.

Perhaps the best way would take an average of the 125mm² and the 151mm². That's probably a reasonable assumption.

You did mention the lack of 19/.103, this should be 19/153.

if you could assist with the larger cable that would be much appreciated.

Steve

 

[Lucien Nunes]

Feel free to mash the winner button if you like the service!

I didn't get round to the later Enfield 19/.064 cable yet, that is more likely to be of similar construction to your 1960s cable as they were probably both made to the later British Standard. The lead is significantly thinner so we should calculate that before making a final call on the sheath resistance.

Re the larger cable, I can't make sense of the '19/153' or '19/1.53' as given earlier.

• 19/1.53 is a valid metric cable stranding for 35mm²
• Trying to read it as an imperial size '19/.153' would make it 225mm²
• My reference to 19/.103 was a top-of head attempt to match it to your comment that it was 95mm² equivalent. 19/.103 did exist as a stranding and is just over 95mm², but does not seem to have been used as a core of PILC.
• 95mm² equivalent imperial size as a PILC core invariably seems to have been 37/.072

So we really need to clarify that number and gather any other possible information before we can make headway with the larger cable.